Dry adapter for fire-extinguishing sprinkler systems



June 2, 1964 F. J. LEE 3,135,331

DRY ADAPTER FOR FIRE-EXTINGUISHING SPRINKLER SYSTEMS Filed Sept. 24,1962 INVENTOR. fZ'a/p L/ LEE 3,135,331 DRY ADAPTER FORFIRE-EXTHNGUISEHNG SPRENKLER SYSTEMS Floyd J. Lee, 119 N. Yale St,Fullerton, Calif. Filed Sept. 24, 1962, Ser. No. 225,696 6 Claims. (Cl.169-17) This invention relates to dry adapters for fire-extinguishingsprinkler systems, and included in the objects of this invention are:

First, to provide a water-free or dry adapter which is connected to awater-filled, fire-extinguishing system so as to extend from the supplylines of the system maintained above freezing temperatures into regionswhich may be maintained below freezing temperatures, such thoughprimarily adapted to carry a single sprinkler head, may be arranged tocarry several.

' Fourth, to provide a dry adapter which may be filled with an inert gasat a selected pressure above supply line pressure, or may be filled orpartially filled and pressurized with a liquid having a low freezingpoint.

Fifth, to provide a dry adapter which incorporates a telltale or bleedvalve operable at a predetermined pressure above line pressure so that,in the event of leakage from the adapter to the supply line, the bleedvalve will open as a warning of such leakage; and wherein, should thebleed valve or sprinkler itself leak, the pressure in the adapter willdrop to cause full opening of the bleed valve, thus creating in eithercase a warning condition which will demand attention.

Sixth, to provide a dry adapter which, on sudden release of pressure,such as caused by collapse of the fuse assembly of the sprinkler head,ensures prompt delivery of water from the water supply system.

With the above and other objects in view, as may appear hereinafter,reference is directed to the accompanying drawings in which:

FIGURE 1 is a fragmentary, substantially diagrammatical viewillustrating one manner in which the dry adapter for fire-extinguishing,sprinkler systems may be installed, wherein the adapter and sprinklerprojectdownwardly from a ceiling;

FIGURE 2 is a similar fragmentary, diagrammatical view, showing theadapter extending horizontally through a wall and the sprinklerdepending therefrom;

FIGURE 3 is a similar fragmentary, diagrammatical view, showing the dryadapter extending horizontally and the sprinkler in an upstandingposition;

FIGURE 4 is an enlarged, longitudinal, fragmentary, sectional view takenthrough 44 of FIGURE 1;

FIGURE 5 is a transverse, sectional view taken through 55 of FIGURE 4;

FIGURE 6 is a sectional view of the inlet plug shown in FIGURES 4 and 5,and illustrating the manner in which the inlet valve is supported duringcharging of the dry adapter;

FIGURE 7 is an exploded view showing the parts of the telltale valvestructure.

The dry adapter for fire-extinguishing, sprinkler systems is arranged tobe attached to a water supply line 1 by a T-fitting 2 or otherconventional fitting. The dry adapter includes a casing 3 which may beformed from a United States Patent 0 a length of pipe having pipethreads 4 at its extremity.

The casing 3 may extend downwardly from a fitting 2 through a wall 5into a region wherein the temperature may drop below the freezing pointof water. Alternatively, the casing 3 may extend horizontally through awall, as shown in FIGURES 2 and 3.

The extended end of the casing 3 receives a reducer fitting 6 or areducer elbow 7 which may be confidential. That is, in either case, thereducer fitting 6 or reducer elbow 7 is provided with an internallyscrew-threaded end so as to form a tightly sealed connection with thecasing 3, and a reduced end also internally screw-threaded arranged toform a tightly sealed connection with a conventional sprinkler head 8,of the type which incorporates a fuse. i

The inlet end of the casing 3 is internally screwthreaded to sealinglyreceive an inlet plug 9. The inlet plug is provided with an offset bore10. The axially inner end of the bore 10 forms a seat which is closed byan inlet check valve 11 having a tapered seat 12.

The inlet check valve 11 extends inwardly from the inlet plug 9 and isprovided with a cross bore which receives a mounting wire 13. Themounting wire 13 is L-shaped to form a laterally extending end whichextends transversely through a screw pin 14, screw-threaded into theinlet plug 9 at one side of the bore 10. p

The reducer fitting 6 or reducer elbow 7 is modified slightly byproviding a fiat area on one side. A screwthreaded bore is formedthrough the fitting and the end of the casing 3 therein, as shown inFIGURE 4. The screw-threaded bore thus formed receives an internallyscrew-threaded fitting 15 having a bore 16 counterborcd at its innerend, and forming a valve seat which is closed by a telltale valveelement 17.

The valve element 17 is provided with a head 18 sealingly engaging thebore 16, and a stem 19 projects into the bore 16. The stem 19 isprovided with a transverse opening through which is threaded a pull wire21 the ends of which initially extend outwardly through the fitting 15.A spring 21 is located within the screwthreaded fitting 15 and bearsagainst the valve element 17, tending to lift the valve element from itsseat.

The screw-threaded fitting 15, valve element 17, and associated partsform a telltale valve unit.

With reference again to the inlet valve 11, initially a screw-threadedstem 22 is inserted into the inlet valve 11 through the bore 10. Thestem 22 is mounted within a sleeve 23, which in turn is fitted withinthe bore 10 and is provided with a shoulder 24. The stem 22 is providedwith a head 25 and a spring 26 bears against the head 25. An internalshoulder 27 is provided within the sleeve 23 so as to hold the inletvalve 11 in yieldable engagement with the bore 10.

Operation of the dry adapter for fire-extinguishing, sprinkler systemsis as follows:

The dry adapter structure is assembled by connecting the reducer fitting6 or the reducing elbow 7 with the casing 3 and connecting the sprinklerhead '8 therewith, and in addition inserting the assembled inlet plugunit as well as the telltale valve unit.

In the initial assembly, the inlet valve 11 is equipped with the stem 22and sleeve 23. The inlet head of the casing 3 is then connected to asource of pressure fluid which is forced into the casing 3 through theinlet valve 11, it being understood that the stem 22 and sleever 23 fitsufficiently loose to permit flow of the pressure fluid into the casing3.

The pressure fluid may be an inert gas or may be a liquid having a lowfreezing point, or may be a liquid and gas mixture. In any case, thefluid is such that it will not freeze at the temperatures to which thesprinkler head 8 may be subjected.

The pressure at which the casing 3 is charged is substantially above theline pressure of the water supply system to which the dry adapter is tobe attached. For example, if the line pressure is 100 pounds, the casing3 would be pressurized to 200 pounds. During the course of charging thedry adapter, the pull Wire or wires 20 are held manually or by asuitable tool as to maintain the valve element 17 closed against theforce of the spring 21, until the internal pressure is suflicient tomaintain the valve element 17 closed. Thereafter, the pull wire 24) isclipped, as indicated in FIGURE 4, or pulled free of the valve element17. After the dry adapter has been pressurized, the sleeve 23 and stem22 are removed.

The dry adapter is installed by screw-threading the upper end containingthe inlet plug 9 into a water supply system. Should any leak occur atany of the joints confronting the interior of the casing 3, or shouldthe sprinkler leak or should the telltale valve element 13 leak, orshould the inlet valve 11 leak back into the water supply line 1, thepressure within the casing 3 will drop to the pressure at the supplyline 1.

The force of the spring 21 is so calculated that it will open thetelltale valve at some pressure above the line pressure. For example, inthe condition given previously, the telltale valve may be designed toopen at 125 pounds. Once the telltale valve opens, the internal pressurewill continue to drop to a point below line pressure, causing the inletvalve 11 to open. Sufficient water will flow out visually to indicatemalfunctioning of the dry adapter.

If desired, the pressure fluid may include a liquid containing a dye tomake more apparent any flow through the telltale valve.

In the event of a fire, the fuse, which normally holds the sprinklerclosed, gives way so that the sprinkler opens. The pressure in thecasing 3 rapidly drops so that the inlet valve 11 quickly opens andallows the Water to flow to and through the sprinkler. At this time thetelltale valve may open, but the dimensions of the bore through thetelltale valve are such that the amount of water lost through thetelltale valve in no'way interferes with the functioning of thesprinkler.

While a particular embodiment of this invention has been shown anddescribed, it is not intended to limit the same to the exact details ofthe construction set forth, and it embraces such changes, modifications,and equivalents of the parts and their formation and arrangement as comewithin the purview of the appended claims.

What is claimed is:

l. A dry adapter for fire-extinguishing, sprinkler systems having awater supply line and sprinkler heads, said adapter comprising: 7 I

(a) a hollow casing having an inlet end for connection to said supplyline and an outlet end for connection to a sprinkler head;

(b) a pressure fluid contained in said casing at a pressure above thenormal pressure at said supply line;

() acheck valve in the inlet end of said casing for admitting waterthereto, said check valve being held closed against the pressure in saidsupply line by reason of the pressure exerted by said pressure fluid;

(d) a telltale valve disposed in a wall of said casing, and alsomaintained in its closed position by said pressure fluid;

(e) and a spring operable to open said telltale valve in the event thepressure of said pressure fluid drops below a predetermined value,thereby to cause flow of detectable fluid from said telltale valve.

2. A dry adapter for fire-extinguishing, sprinkler systems having awater supply line and sprinkler heads, said adapter comprising:

(a) a hollow casing havingan inlet end for connection to said supplyline and an outlet end for connection to a sprinkler head;

(b) a pressure fluid contained in said casing at a pressure above thenormal pressure at said supply line;

(0) a check valve in the inlet end of said casing for admitting waterthereto, said check valve being held closed against the pressure in saidsupply line by reason of the pressure exerted by said pressure fluid;

(d) a telltale valve bore in said casing at said outlet end at one sideof its connection to said sprinkler head;

(e) a telltale valve in said bore and maintained in its closed positionby said pressure fluid;

(f) and a spring operable to open said telltale valve in the event thepressure of said pressure fluid drops below a predetermined value,thereby to cause flow of detectable fluid from said telltale valve.

3. A dry adapter for fire-extinguishing, sprinkler systems having awater supply line and sprinkler heads, said 15 adapter comprising:

(a) a hollow casing having an inlet end for connection to said supplyline and an outlet end for connection to a sprinkler head;

(b) a pressure fluid contained in said casing at a pressure above thenormal pressure at said supply line;

(c) a check valve in the inlet end of said casing for admitting waterthereto, said check valve being held closed against the pressure in saidsupply line by reason of the pressure exerted by said pressure fluid;

(d) a telltale valve bore in said casing at said outlet end at one sideof its connection to said sprinkler head;

(e) a telltale valve in said bore and maintained in its closed positionby said pressure fluid;

(f) a'spring operable to open said telltale valve in the event thepressure of said pressure fluid drops below a predetermined value,thereby to cause flow of detectable fluid from said telltale valve;

(g) and a tension means attached to said telltale valve and initiallyextending through said casing for drawing said telltale valve to itsclosed position against the action of said spring prior to pressurizingsaid casing.

4. A dry adapter for fire-extinguishing, sprinkler sys- 4 terms having awater supply line and sprinkler heads, said adapter comprising: 7 g

(a) a tubular casing having an inlet end for connection to said supplyline and an outlet end;

(b) means at said inlet end forming an inlet port hav- H ing a valveseat facing into said casing;

49 (c) an inlet valve closing said valve seat and movable into saidcasing for admitting water from said supply line;

(d) a fitting at the'outlet end of said casing adapted for connection toa sprinkler head;

50 (e) means defining a telltale valve bore at the outlet portion ofsaid casing;

(f) a telltale valve in said valve bore, and having a head within saidcasing for sealing engagement with said a bore; 5

(g) means for filling said casing with a fluid to a pres- 1 sure abovethe pressure in said supply line to hold both said inlet valve and saidtelltale valve closed;

(h) and a spring operable to open said telltale valve in the event ofleakage of said fluid and consequent re- 69 duction in pressure to apredetermined value between its initial pressure and said supply linepressure.

5. A dry adapter for fire-extinguishing, sprinkler systems having awater supply line and sprinkler heads, said adapter comprising:

(a) a tubular casing having an inlet end screw-threaded for connectionto a Water supply line, and an outlet end;

(1)) a plug sealed in said inlet end and having an inlet bore;

7 O (c) an inlet check valve within said casing for closing said boreagainst backfiow from said casing to said supply line;

(01 a fitting at said outlet end adapted to receive a thermally operablesprinkler head;

(e) and a telltale valve unit disposed in a wall of said casing, andincluding a check valve bore of small (a) yieldable means is providedfor initially closing diameter for limited flow of liquid from saidcasing, Said inlet check Valvfl;

a telltale check valve responsive to pressure in said (5) other means isN for l closflg casing to close said bare and a spring tending to saidtelltale check valve during pressunzmg of said open said telltale checkvalve when the fluid pressure 5 casmg' in said casingdrops belowapredetermined value. References Clted m the me of thls patent 6. A dryadapter for fire-extinguishing, sprinkler sys- UNITED STATES PATENTS1,903,150 Tyden Mar. 22, 1933 terns as set forth in claim 5, wherein:

1. A DRY ADAPTER FOR FIRE-EXTINGUISHING, SPRINKLER SYSTEMS HAVING AWATER SUPPLY LINE AND SPRINKLER HEADS, SAID ADAPTER COMPRISING: (A) AHOLLOW CASING HAVING AN INLET END FOR CONNECTION TO SAID SUPPLY LINE ANDAN OUTLET END FOR CONNECTION TO A SPRINKLER HEAD; (B) A PRESSURE FLUIDCONTAINED IN SAID CASING AT A PRESSURE ABOVE THE NORMAL PRESSURE AT SAIDSUPPLY LINE; (C) A CHECK VALVE IN THE INLET END OF SAID CASING FORADMITTING WATER THERETO, SAID CHECK VALVE BEING HELD CLOSED AGAINST THEPRESSURE IN SAID SUPPLY LINE BY REASON OF THE PRESSURE EXERTED BY SAIDPRESSURE FLUID; (D) A TELLTALE VALVE DISPOSED IN A WALL OF SAID CASING,AND ALSO MAINTAINED IN ITS CLOSED POSITION BY SAID PRESSURE FLUID; (E)AND A SPRING OPERABLE TO OPEN SAID TELLTALE VALVE IN THE EVENT THEPRESSURE OF SAID PRESSURE FLUID DROPS BELOW A PREDETERMINED VALUE,THEREBY TO CAUSE FLOW OF DETECTABLE FLUID FROM SAID TELLTALE VALVE.